William hopkin akester



' UNITED STATES PATENT OFFICE.

\VILLIAM HOPKIN AKESTER, OF FULI'IAM, ENGLAND.

COMPOUND FOR FROSTING GLASS.

SPECIFICATION forming part of Letters Patent No. 445,528, dated February 3, 1891. Application filed June 26, 1890. Serial No. 356,877. (No specimens.) Patented in Belgium April 28, 1890, No, 94,037.

To all whom it may concern:

Be it known that I, \VILLIAM IIOPKIN AKESTER, electrician, a subject of the Queen of Great Britain, residing at No. 15 Munster Road, Fulham, in the county of Middlesex, England, have invented new and useful Improvements in Compounds for Frosting Articles of Glass, of which the following is a specification.

This invention relates to improvements in a compound for frosting articles or surfaces of glass and such as the exterior surfaces of the globes of incandescent electric lamps, whereby the desired object is attained in a more simple, economic, and effective manner than heretofore. For this purpose the surface of the article to be frosted or obscured is first thoroughly cleansed by any suitable means which will render it chemically clean, such as methylated spirits, and the article is then dipped into a bath consisting of nitrocellulose dissolved in acetate of amyl. In preparing the bath I take a quantity of that form of nitrocellulose known as the ordinary gun-cotton of commerce and place it in a closed vessel, and I add thereto a quantity of acetate of amyl, so that the consistency of the solution will be such that it will run freely. To insure the intimate combination of the nitrocellulose with theacetate of amyl, the vessel containing the solution. is agitated or the latter is stirred from time to time.

When treating articles which are of such form and dimensions as to render the dipping operation impracticable or inconvenient, I apply the bath solution to the surface of the article by the aid of a brush or other suitable means; or I may cause the solution to flow onto and over such surface and then permit any excess to drain off.

The article which has been coated with the solution in the manner above described I now place in a drying-chamber, which is heated to a temperature of about 100 Fahrenheit by means of steam or hot water circulating through suitable pipes, and through which chamber a current of air is caused to pass,

and I allow it to remain in the chamber nntil the solvent of the solution has completely evaporated; or in lieu of employing the steam or hot-water circulation pipes to furnish the necessary heat to carry 01f the solvent I may cause the current of air to be heated to atemperature of about the same degree before passing into the drying-chamber.

In order to give to the article to be treated the appearance of ground glass, I add to the bath solution hereinbefore described from about five to fifteen per cent, by weight, of finely-divided kaolin; or I may employ any like silicate of alumina or gypsum in suitable proportions.

hen it is desired that the article should be coated with a colored film, I add to either of the bath solutions hereinbefore described any suitable coloring-matter, such as colored earth, but preferably the aniline series of dyes; or when combining pigment with the bath solution I may dispense with the aniline or other like coloring-matter and employ colored earth in place of kaolin or other colorless material. By adding a clear coloring materialsuch -aniline-to the bath solution herein first described I am enabled to obtain a comparatively clear and transparent film upon the article.

I would here remark that I do not confine myself to the precise proportions of the ingred ients hereinbefore given, as the same will admit of considerable modification without departing from the peculiar character of my invention.

hat I claim is- The herein-described compound for frosting articles of glass, consisting of a solution of nitro-cellulose in acetate of amyl, to which solution has been added kaolin or other like silicate of alumina or gypsum.

WILLIAM l-IOPKIN AKESTER.

\Vitnesses:

GEo. S. VAUGHAN, 57 Chancery Lane, London.

T. F. BARNES,

28 Southampton Buildings, London, W. O. 

